In situations where an individual has damaged, or had a surgical procedure on, an ankle or foot it is preferred medically to keep weight off the foot or ankle while recuperating. Traditionally, this has been achieved by the use of wheelchairs or crutches. However, wheelchairs can be undesirable for many reasons such as access. Also, not everyone is able to use crutches due to the possibility of weakness or inconvenience. Accordingly, a device known as a “knee-walker” has been developed in the past to support the injured leg while providing stability such that the individual may still move around on their own. Such knee-walkers are known from U.S. Pat. No. 4,867,188, U.S. Pat. No. 5,800,317 and U.S. Pat. No. 7,311,319. With regard to these prior art devices, they all have certain deficiencies such as the inability to steer them effectively, especially on uneven terrain, and instability. Accordingly, it is desirable to have an improved knee-walker.